Gun rifling machine



y 1943 w. F. GROENE AL 2,319,451

GUN RIFLING MACHINE Filed June 18,' 1941 7 Sheets-Sheet l INVENTOR.

MHLTER R. MEYER 7 May 1943 w. F. GROENE EFAL GUN RIFLING MACHINE Filed June 18, 1941 7 Sheets-Sheet 2.

INVENTOR. vuLuFm F. GROENE BY V MAL-rue R. MEYER May 18, 1943 w. P. GROENE EI'AL GUN RIFLING MACHINE 7 Sheets-Sheet 3 Filed June 18, 1941 INVENTOR WILLmM F. QROENE WRLTER R. NEXER \DLQQ A, 9AM

May 18, 1943 w. F. GRCIJENE ETAL GUN RIFLING MACHINE Filed June 18, 1941 7 Sheets-Sheet 4 INVENTOR. w\\ mm.\-'. QRQEHE WALTER R. MEYER May 18, 1943 w. F. GROENE ETAL.

GUN RIFLING MACHINE Filed June 18, 1941 7 Sheets-Sheet '7 EM E INVENTQR.

wmunm F. QRQENE HLTER R.ME(ER Patented May 18, 1943 cinnati, Ohio, assignors to'TheR. KL lie Bl'ond Machine.v Tfool. Gompany, Cincinnati; Ohio, a.

corporation. of; Delaware ApplicationJilne 18, 1941, Serial"No..398;6.46'

5. Claims.

This invention pertains tov a machine. for cutting, the rifling in thebores of guns andii'sparticular-ly related to a method and apparatus. for breaching the rifling grooves in the gunlbore.

More. particularly, this invention pertainsto a. novel arrangement for supporting the. broaching.

bar. which carries the broaching discs. which. are forcedthroughthe bore of the. gun. to effectlthe cutting of the rifling grooves therein.

Present day accepted practice inrifiihg guns is that of broaching these grooves. by pushing, a series of broaching discs through thepreviously bored gun and to successively presentth'ese. various broaching discsin the. bore of the gun until' the rifling has been. prepared to the proper. depth and". size. These. breaching. discs are carried, on. a

pilotshankwhich is mounted. on the end. of the. bar and which is guided in. the. bore. of the gum,

' Because of. the nature. of the. chipslremovedby the broaching disc cutters, itis. necessary that. the cutters precede any portion of the broachi'ng bar or the pilot shank fixed on the end. of the bar so that the chips cut by the cutter d'olnot interfere, with the. proper sliding. actionofi'the shank in. the bore ofthe. gun, The. result" of this. fact is that the cutter must be pushed. by the broaching bar, through thebore ofjthegun. to. effect the rifling operation. This necessary pushing, ac-

tion causes. the broaching barslto, tend to. bendv or spring sideways under compressiveiorceszset' i up by the, cutting action. ofjthe. breaching. disc. cutters in the riflinggrooves offthe. gun. so that difficulty is. experiencedwithproperly holding this breaching bar rigidly against, axial. bending and chatter which results fromthi's type of distortive movement in the rifling bar. It is. therefore one ofthe chief objects of this invention. to' eliminate,

entirely this difiiculty of. the. bending of. the

breaching bar duringthe cutting action, of. the.

broaching cutters in the gun;

Another object of this invention,,is. to provide means-for preventing the bendingoi'the bro'ache ing bar by accurately and. positively guidingthe broaching bar along its entirelength both in the bore-of'the gun and also when outside" ofthe' bore of the gun, so that'nopossiblebendingaction sideways can take place-in the -broaching bar. This, of course, results in very accuratemachining of' the grooves of the riflingin the gun and also completely eliminates the initial: chattered or distorted portions which have heretofore occurred in the gun at' the. beginning. of. thebroaching stroke. In the past,.. inorder. to eliminate thischattered portion orthegun, .itzwas, ioundanecessarydso makezthegumoversizeinover all lengthand tocut off thisportion of'the gun after the riflinghad been. complete. Thus with this. arrangement, thisunnecessary, wasteful',,and costly procedure, has been. eliminated;

And. still another object of this. invention is to provide in an apparatus for broaching' the riflinggrooves. in guns a breaching bar arrangement, and a spirally. grooved. bar arrangement associated-with. the boring bar, soarrangedithat. ,7 the spiral guide. grooves for. giving the lead to the riflingdo. notLat any time: enter the. borel of the gun nor become. exposed. to. thechips or any foreign matter. removed. from the. gun. bore during. the. rifiing. operation.

Further features; andadvantagesoi this invention will appear. from a detailed description of the drawingsinwhifchL Figure. 1' is: a frontelevati'onal; view. of a ma: chine incorporating. our novel process. and. ar rangement for rigidly guiding. the, rifling broaching bar positively at all; times'both. in the gun bore. and when outside of said gun bore.

Figure l'l isa plan view of. the. rifiingmachine shown inFig-ure. LI

Figure. III is, an enlarged. fragmentary. plan view of: the left handendofjthe. rifiing machine shown in Figure I,. particularly showing the mountingfor thegun'to. be rified on the. bed of the, machine;

Figure. IV is an, enlarged fragmentary plan view of 'the.centrali.portion Qfthemachine par.-

ti'cularl'y showing the guiding means for rigidly supporting the broaching bar. against sidewise bending when outsideofthe bore. of the gun. to

FigureV. is. adetail'ed' plan view on the line V -V of. Figure... of the housing. for carrying the supporting. members for therifle. broaching bar when. removedtfitomithe bore offthe. gun..

Figure VI; is an enlarged fragmentary pl'an view-ontheright. hand end; of the, rifling machine shownin Figure I; particularly, showing the rifle groove. guide'bar for rotating the broachingibar for. effiectingthe proper leadffor the rifling grooves and'lalso showing, the drive. for actuating the. breaching; bar. carriage longitudinally of. the machinebed'. r

Figure. Vllis a. fragmentary. sectional .view. on

the. line VII-VII of Eigl118SrI, IV. and VIII, particularly' showing; the. supporting members. for the rifiing bar, when-outsideof the gunbore and. also the spiralguide grooves; inthe spiral. guide bar arrangement for rotating the breaching bar ior-g'efiecting, therpropenlead in-t-he. rifling; inthe.

Figure VIII i a fragmentary sectional view on the line VIII-VIII of Figures II, V, and VII, showing the operating mechanism for controlling the motion of the supporting means for the broaching bar when out of the gun bore.

Figure IX is an enlarged detailed sectional view through the broaching disc shank showing the broaching disc mounted thereon and in connection to the broaching bar as illustrated on the line IXIX of Figures X, XI, and XIII.

Figure X is a face View of the broaching disc shown on the line X-X of Figure IX.

Figure XI is a sectional view through the broaching disc shank showing the coolant distributing holes in the shank and pilot bush on the line XIXI of Figure IX.

Figure XII is a section through the gun barrel on the line XIIIHI of Figure XIII showing the rifiing in the gun when completed by the broaching disc cutter.

Figure XIII is an enlarged fragmentary section through the gun and showing the broaching disc and shank and broaching bar in the bore of the gun near the end of a stroke through the gun during the rifiing operation, as shown on the line XIII-XIII of Figure XII.

The machine comprises a bed I, which is suitably mounted on supporting legs 2, 3, 4, and 5. On top of the bed are provided suitable ways 6 and 1 extending longitudinally the entire length of the top of the bed. On the bed is provided suitable work carrying members 8 and 9, in which may be securely mounted a gun I6 preparatory to cutting the rifiing grooves in its bore which has been previously machined.

Midway of the bed I of the machine, is provided the apparatus for accurately and positively guiding the rifiing bar H, on which is mounted the broaching disc cutter 2. This arrangement comprises a housing 3, Figure V, which is securely bolted to the bed I of the machine by'suitable screws I4. This member l3 has a bottom surface l5 and side surfaces 6 and l! and also a top surface l8 formed by a cover plate I9 securely bolted to the top sur face 26 of the housing member I3. Between these surfaces l5, I6, H, and I8 are carried a series of accurately sliding blocks 2|, 22, 23, and 24 and a block 25 which is connected to the rifiing bar H by a suitable key 26 fixed to the block 25 and engaging in a notch 21 formed in the bar ll.

In each of these blocks 2|, 22, 23, and 24 is formed an accurate bore 28 the same size as the bore 16 of the gun to be rifled, in which the peripheralsurface 26 of the broaching bar II is free to nicely slide in accurately guided position.

The periphery 29 of the broaching bar H is relieved by a spiral groove 23a (not related to the spiral of the rifiing grooves) to eliminate too great a frictional contact between the surface 29 and the bores in the blocks 2|, 22, 23, and 24 and the bore 16 in the gun l0 and to provide space for fine particles of foreign matter resulting from the cutting action of the tool in the bore of the gun. The broaching bar H is connected through a suitable tapered socket arrangement 36 to the actuating spiral guide bar 3i, which is arranged to freely slide in a. guide bushing 32 fixed on the right hand end of the housing l3 fixed in a bracket 33 on the right hand end of the housing 3. Also on this bracket 33 are fixed the blocks 34 by suitable screws 35 in which are adjustably carried the studs 36 which are adjustable by suitable thumbnuts 37 and which studs in turn are connected to the guide keys 38 which operate in the spiral guide grooves 39 formed in the guide bar 3| for effecting the rotation of the bar 3| and thereby the broaching bar II in proper lead for the correct spiral angle for the rifiing groove as the bar 3| is advanced longitudinally of the gun barrel.

This longitudinal movement of the guide bar 3| is effected by means of the guide bar carriage 46 which is slidably mounted on the bed ways 6 and and has the upper projection 4| in which is rotatably mounted against axial movement the guide bar 3|. The carriage 40 may be actuated along the bed ways 6 and at appropriate feeding speeds by the usual feed screw 42, which is driven through suitable transmission means in the casing 43 by the motor 44.

On the outer end of the rifiing bar II, is mounted the broaching disc cutter shank 45 by a suitable threaded connection 46 in the'hollow bore 41 of the bar II. By rotating the shank 45 in the thread 46, the pilot bushing 48 may be securely locked between the end face 49 of the rifiing bar II and the face 50 formed on the annular enlarged portion 5| of the shank 45. On the outer end of the shank 45 is mounted the broaching disc l2, which has a series of projecting cutting edges 52, as best seen in Figure X, corresponding to each of the grooves 53, Figure XII, to be cut in the bore 16 of the gun It]. This cutter is securely mounted on the shank 45 by the nut 54 threaded on the portion 55 of the shank 45 and is thereby drawn tightly against the face 56 of the portion 5| of this shank. A suitable key 5'! fixed in the shank 45 by a suitable screw 58 and having an enlarged outer portion entering into the slot 59 provided in the broaching disc cutter I 2, serves to prevent relative rotation of this cutter on the shank 45.

Coolant is also provided for the shank for cooling and lubricating the cutter and lubricating the sliding of the pilot bushing 48 and the boring bar II in the gun bore and also in the bores 26 of the blocks 2|, 22, 23, and 24, as described. This coolant and lubricating medium is provided by suitable conventional hydraulic pump 60 which takes coolant medium from the reservoir 6| and transmits it through the lines 62 and 63, into the bore 64 in the guide bar 3| and then into the bore 41 of the rifiing cutter bar II and then into the bore 65 in the shank 45, from which bore 65 radiates the distributing holes 66 which open into an annular groove 61 formed therein. Thepilot bush 48 is formed with a series of slots 68, which communicate with this annular groove 61 to thereby distribute the coolant to the surfaces of the pilot bush and the boring bar H, to thereby lubricate these liding members and also to effect the cooling of the broaching disc cutter |2 and to wash the chips ahead of the cutting edges 52 of the cutter out of the left hand end of the bore of the gun as the rifiingproceedsr The operation ofthis arrangement is substantially as follows:

Assuming the broaching bar II to be fully retracted from the bore of the gun ID as shown in Figure IV, the various supporting blocks 2|, 22, 23, 24, and 25, it will be distributed along the housing I3, as shown in Figure IV, as will be described. 'Likewise, the grooved guide bar 3| will be'retracted to the right, as shown in Figures IV guide bushing, 4-l'a fixed: in thehracket l3. toward the gun I05, As the;bar|:-| thusbeginstomove tothe left, FigureVIII", it. will. normally tend to slide its periphery 2a:in=thevariousbores 2 8 or the blocks.2.|; 22, 2.3; and 24, these; blocks normallyremaining: unmoved: in. the bracket I3 until the block 24 is engaged:- by the-block 25 :fixed on. the bar |-|.v this; block-Mi: comes into engagement with the block 24:, its latch pin 69 will engage under; the latch lfl pivotally. mounted one the block 24 by a suitable pin, III. and, will latchitself under. the outer end 12 of theI-latch llhand while in such aposition will also be moved; along by the block 25, which abuts, against" it, as; the. rifiing bar. is moved to the gun barrel. Likewise the similar. latches 13, I4, and-l5; will also engage the respective pins 69 of the, blocks; 23, 22 and 2|, so; that. whenthe breaching bar l.|-final ly reaches the end of its stroke withitscutter l2 projecting-out from the left hand end of the gun Hi, all of these blocks, will have, been, accumulated together at the left;hand end,of;thehousing l3 and will all be latched together by the respective latches I0, 13, 14, and I5.

During this forward movement of the broaching bar its periphery 29 will also ride in nice sliding contact with the bore 16 of the gun barrel, so as to rigidly support this bar its entire length in the bore of the gun. In addition to the normal support offered the cutter by the pilot leads 48, which also nicely slides in the bore 16 of the gun, as described.

After the cutter |2 has thus completed a pass through the bore of the gun, it is then removed and the bar H and shank 45, fixed thereon, is returned to the right hand end of the gun for the insertion of a new cutter of slightly larger size again on the shank for another pass through the gun bore. This return movement of the rifiing bar H by reversal of the motor 49 which draws the carriage 40 to the right, causes the block 25, which under these conditions is now latched to all of the blocks 24, 23, 22, and 2|, to begin to draw these blocks likewise backwardly to the right until the first block has its pawl 11 engaged by a knock-off pin 16, fixed in the housing l3, a predetermined distance from the left hand end thereof. The result of engagement of the pawl 15 with this pin 16 causes the latch to release the block 2| from the rearward motion caused by the return of the bar H and to thereby leave this block 2| at this predetermined position. An additional projecting surface I1 is also formed on the pawl 15, which may positively engage 7 against the side of the pin 16 in the event friction between the surface 29 of the bar II and the bore 28 of the block 2| would tend to cause this block to creep out of its predetermined position it is to be stopped in for supporting the bar. Similarly, each of the respective pawls l4, l3, and 10 are likewise engaged at predetermined intervals by pins 18, 19, and 80, all of which pins are staggered, as shown best in Figure V, so that each of the respective blocks 2|, 22, 23, and 24, will this wayxthehar is again brought into condition for returninto the gun, bore for another cutting operation. after a, new; and, slightly larger cutter: |2rhas:been.placed;on theshank 45.

It;wi-ll;thus beseen that. withthis arrangement the riding bar H is not only supported by the pilot: bushon the shank, and in the spiral groove guide ban3l, but is: also. supported at alltimes throughout its entire length whetherit is: in the gun bore, or whether it is fully removed? from the gun: bore. It. is also-to be noted that the'rifling bar' is arranged'to be supported ataapredetermined number of positions as it progressively moves. in. or out. of the gun bore in which it is also fully supported: during" the rifiing operation.

Having thus fully set forth and described our invention whatwe claim asnew and desire to.se-- cureby United. States Letters Patent is:

1. In a gun rifiing machine, a bed, means on said: bed for rigidly-supporting a gun to berifled longitudinally of said'bed, arifling carriage movable on said bed to and from said gun, a spiral guide bar connected rotatably to said carriage formovement longitudinally of said bed, a rifiing bar connected to the end of said: spiral guide bar, meansv for supporting said spiral guide bar on said bed, and means in said supporting means operating'in the spirali groove of said guide bar and riflingbar; and meansbetween said supporting, means fonsaid guide bar and saidgunfor rigidly supporting, saidrifiing bar for. any posi tion of relative movement of said rifiing carriage on said bed, said means comprising a housing fixed on said bed, a series of slidable blocks mounted for accurate sliding movement longitudinally of said bed in said housing, a series of bores in each of said blocks through which said rifiing bar nicely slides, and means for automatically distributing said blocks at spaced intervals in said housing by the movement of said rifiing bar into or out of said barrel.

2. In a gun rifiing machine, a bed, means on said bed for rigidly supporting a gun to be rifled longitudinally of said bed, a rifiing carriage movable on said bed to and from said gun, a, spiral guide bar connected rotatably to said carriage for movement longitudinally of said bed, a rifiing bar connected to the end of said spiral guide bar, means for supporting said spiral guide bar on said bed, and means in said supporting means operating in the spiral groove of said guide bar and rifiing bar, and means between said supporting means for said guide bar and said gun for rigidly supporting said rifiing bar for any position of relative movement of said rifiing carriage on said bed, said means comprising a housing fixed on said bed, a series of slidable blocks mounted for accurate sliding movement longitudinally of said bed in said housing, a series of bores in each of said blocks through which said rifiing bar nicely slides, and means for automatically distributing said blocks at spaced intervals in said housing by the movement of said rifiing bar into or out of said gun barrel, and means on said rifiing bar engaging the bore of said gun for supporting said rifiing bar when in said gun bore.

3. In a rifiing machine, a frame, means for rigidlymounting a gun on said frame, a rifiing bar carriage movabl on said frame relative to said gun, a rifiing bar fixed on said carriage for movement into or out of the bore of said gun, and means for supporting said rifiing bar when removed from the bore of said gun comprising a series of supporting members mounted on said frame arranged at a series of predetermined positions between said carriage and said gun, and means for automatically orienting said supporting means at said predetermined positions by the movement of said rifiing bar out .of the bore of said gun.

4. In a rifiing machine, a frame, means for rigidly mounting a gun on said frame, a rifiing bar carriage movable on said frame relative to said gun, a rifiing bar fixed on said carriage for movement into or out of the bore of said gun, and means for supporting said rifiing bar when removed from the bore of said gun comprising a series of supporting members mounted on said frame arranged at a series of predetermined positions between said carriage and said gun, and means for automatically orienting said supporting means at said predetermined positions by the movement of said rifiing bar out of the bore of said gun, said means comprising a series of latches on each of said supporting means arranged to engage their associated supporting means as said rifiing bar is moved into said gun bore and means on said frame for actuating said latch means at said predetermined location for arresting further movement of each of said supporting means at.

a particular place as said rifiing bar is withdrawn from said gun barrel, so as to position them at a series of spaced intervals for supporting said rifiing bar at a plurality of different points when removed from said gun bore.

5; In a rifiing machine, a frame, means for rigidly mounting a gun on said frame, a rifiing bar carriage movable on said frame relative to said gun, a rifiing bar fixed on said carriage for movement into or out of the bore of said gun, and means for supporting said rifiing bar when removed from the bore of said gun comprising a series of supportingmembers mounted on said frame arranged at a series of predetermined positions between said carriage and said gun, and means for automatically orienting said supporting means at said predetermined positions by the movement of said rifiing bar out of the bore of said gun, said means comprising a. series of latches on each of said supporting means arranged to engage their associated supporting means as said rifiing bar is moved into said gun bore and means on said frame for actuating said latch means at said predetermined location for arresting further movement of each of said supporting means at a particular place as said rifiing bar is withdrawn from said gun barrel, so as to position themat a series of spaced intervals for supporting said rifiing bar at a plurality of different points when removed from said gun bore, and means on said rifiing bar engaging said supporting members and also engaging in the bore of said gun whereby said rifiing bar is supported rigidly against axial bending both when in said bore of said gun, or when removed from said bore.

WILLIAM F. GROENE. WALTER R. MEYER. 

